A liquid crystal display (LCD) device includes an LCD panel formed with liquid crystal cells and pixel structures with each associating with a corresponding liquid crystal cell and having a scan line, a data line, a pixel electrode, and a switch having a gate, a source and a drain electrically connected to the scan line, the data line and the pixel electrode, respectively. Generally, an aperture ratio of pixels directly affects utilization of backlight and panel brightness of an LCD. In a pixel structure, a capacitance, Cpd, between the pixel electrode and the data line is one of major factors affecting the aperture ratio. The capacitance Cpd is determined by the distance between the pixel electrode and the data line. The closer the pixel electrode and the data line are, the larger the capacitance Cpd is. However, when the pixel electrode and the data line are too close, a cross talk may be generated by the coupling effect between the charged potential on the pixel electrode and the signal voltages transmitted in the data line, which deteriorates the display quality of the LCD. Generally, the data line is always designed to be separated from the pixel electrode for a distance so as to avoid the cross talk. However, the longer the distance between the data line and the pixel electrode is, the more greatly the aperture ratio of the pixel decreases.
To reduce the cross talk of the pixel structure and maintain the aperture ratio of the pixel structure at a certain level, various designs of pixel structures have been developed. For example, one of the pixel designs is the utilization of a shielding electrode disposed between the pixel electrode and the data line to reduce the effect of capacitance Cpd. As shown in FIG. 6, in the pixel design, the shielding electrode 640 is formed over the date line 620 and the switch 650, but under the pixel electrode 610, such that the shielding electrode 640 has an area 660 that is overlapped with the peripheral portion of the pixel electrode 610. For such a pixel design, the overlapped area 660 of the shielding electrode 640 with the peripheral portion of the pixel electrode 610 is configured to generate a storage capacitance therebetween, thereby improving the aperture ratio thereof, in comparison with a pixel design without a shielding electrode. However, the shielding electrode 640 is usually formed of an opaque conductive material because of impedance. Thus, the use of the overlapped area 660 of the shielding electrode 640 with the peripheral portion of the pixel electrode 610 to generate the storage capacitance itself reduces certain amounts of the aperture ratio.
Additionally, some pixel designs also utilize a comb-like pixel electrode 710 to assist with the orientations of liquid crystals, as shown in FIG. 7. In the pixel design 700, the storage capacitance area 760 formed by overlapping the shielding electrode 740 with the peripheral portion of the pixel electrode 710 is reduced because of the comb-like structure of the pixel electrode 710. Increasing the storage capacitance area, thereby increasing the storage capacitance, will reduce the aperture ratio.
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.